For several days, the post title was not appearing right for all wp.com blogs aggregated there and on other planets too. The post title was replaced by the blog name part before .wordpress.com. In my case, all posts titles were “bapoumba”.

Adding: feed/?mrss=off at the end of the url did the trick, but I did not investigate further. This was a recommendation from wp.com support to one of the bloggers aggregated there.